1. Field of the Invention
This invention relates to a steering apparatus, and more particularly to a steering apparatus for a vehicle having two front wheels.
2. Description of the Related Art
Referring to FIG. 1, a conventional vehicle 1 having two front wheels includes a frame 11, a central rod 12 disposed pivotally on the frame 11, two suspension units 13 disposed respectively at two opposite sides of the steering rod 12, and a steering unit 15 connecting the suspension units 13 to the frame 11.
Each of the suspension units 13 includes a side rod 131 connected to a front wheel 132. The steering unit 15 includes a mounting seat 151 disposed on a bottom end of the central rod 12, two connecting seats 152 disposed respectively on the side rods 131 of the suspension units 13, and two connecting bars 153 each connected between the mounting seat 151 and the corresponding connecting seat 152. Each of the connecting bars 153 includes a bar body 154, and two joints 155 disposed respectively on two opposite ends of the bar body 154.
When the central rod 12 is rotated, the connecting bars 153 activate the connecting seats 152 to thereby drive rotation of the front wheels 132, so as to achieve steering function.
With further reference to FIG. 2, although rotation can be transferred between the mounting seat 151 and the connecting seats 152 through the bar bodies 154 and the joints 155 of the connecting bars 153, the maximum rotational angle 16 of the joints 155 is only about 22°. As a result, the steering angle of each of the front wheels 132 is limited to thereby affect adversely control of the vehicle 1. Moreover, when the front wheels 132 move on a bumped road surface such that the connecting seats 152 vibrate in a direction 17, since the maximum rotational angle 16 of the joints 155 is small, the joints 155 are subjected to a relatively large load, thereby reducing the service life of the joints 155.